title: Abiotic mechanism for the formation of atmospheric nitrous oxide from ammonium nitrate.
abstract: Nitrous oxide (N2O) is an important greenhouse gas and a primary cause of stratospheric ozone destruction. Despite its importance, there remain missing sources in the N2O budget. Here we report the formation of atmospheric nitrous oxide from the decomposition of ammonium nitrate via an abiotic mechanism that is favorable in the presence of light, relative humidity and a surface. This source of N2O is not currently accounted for in the global N2O budget. Annual production of N2O from atmospheric aerosols and surface fertilizer application over the continental United States from this abiotic pathway is estimated from results of an annual chemical transport simulation with the Community Multiscale Air Quality model (CMAQ). This pathway is projected to produce 9.3(+0.7/-5.3) Gg N2O annually over North America. N2O production by this mechanism is expected globally from both megacities and agricultural areas and may become more important under future projected changes in anthropogenic emissions.
authors.affiliation: Department of Chemistry, Center for Global and Regional Environmental Research, University of Iowa, Iowa City Iowa 52242, United States.
authors.forename: Gayan
authors.initials: G
authors.lastname: Rubasinghege
authors.forename: Scott N
authors.initials: SN
authors.lastname: Spak
authors.forename: Charles O
authors.initials: CO
authors.lastname: Stanier
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Carmichael
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Grassian
mesh_terms: D000393:Air Pollutants / Q000138:chemical synthesis*; D001272:Atmosphere / Q000737:chemistry*; D008956:Models, Chemical; D009566:Nitrates / Q000737:chemistry*; D009609:Nitrous Oxide / Q000138:chemical synthesis*; D055668:Photochemical Processes; D012987:Soil / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D009566:Nitrates; D012987:Soil; D009609:Nitrous Oxide; C006568:ammonium nitrate